It is attempted to use a porous carbon membrane as an active layer in a filtration membrane. The porous carbon membrane has superior durability and the like to those of, for example, polymer membranes such as polyamide based membranes, which were the conventional mainstream as the active layer. In recent years, practical use of the porous carbon membrane is expected.
For example, Patent Document 1 discloses that a porous carbon membrane formed by a plasma chemical vapor deposition (CVD) is used as the active layer, in which hydrocarbon gas such as acetylene is used as a carbon source. The porous carbon membrane has a plurality of pores of about several nanometers, the pores being provided through the porous carbon membrane in the thickness direction. For example, in a filtration experiment using a sodium chloride aqueous solution, the impermeable rate for sodium chloride (the concentration: 34 mM) is 68.5%, and the permeable rate (flux) therefor is 4.7 L/h·m2.
Patent Document 1: Japanese Patent Publication No. 5527662